Question: Simplify the following expression: $n = \dfrac{8k}{9} - \dfrac{k}{4}$
In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $9$ and $4$ $\lcm(9, 4) = 36$ $ n = \dfrac{4}{4} \cdot \dfrac{8k}{9} - \dfrac{9}{9} \cdot \dfrac{k}{4} $ $n = \dfrac{32k}{36} - \dfrac{9k}{36}$ $n = \dfrac{32k -9k}{36}$ $n = \dfrac{23k}{36}$